The Basic Science of Geothermal Heating and Cooling

March 13, 2018

Plenty of people here in Green Bay, WI, have signed on with Action Heating & Cooling Services, LLC to transform their homes into geothermal homes. Still unsure about geothermal heating and cooling yourself? Knowing some of the science behind it – and the mechanics as well – would probably help.

We’ve written elsewhere aboutthe advantages of geothermal heating and cooling. Suffice it to say here that few other methods of maintaining apleasant home environment all year long are as efficient, trustworthy, or economical, especially when you consider the energy savings.

Here’s how geothermal works its magic.

Thar’s GoldHeat in Them Thar Hills!

We tap the earth for precious metals. We tap the earth for oil. Now, as never before, we’re tapping the earth for a resource probably just as valuable to most of us: the energy to heat and cool our homes that doesn’t entail oil.

You see, just below the earth’s crust – that would be roughly 33,000 feet under our feet – is a stratum of magma. This is a molten and semi-molten blend, principally of silicates, in which temperatures run from 1300 degrees Fahrenheit to 2400 degrees Fahrenheit and hotter the deeper you go (not that you’d want to go there!). What this serves to do is keep the ground immediately under the earth’s surface at a year-round temperature of between 45 and 75 degrees Fahrenheit. The upshot? Underground temperatures in Green Bay (and most places stateside, as it were) are warmer than the ambient air above ground in Winter and cooler than the ambient air above ground in Summer.

Time to Get Pumped!

The task, then, of a geothermal heating and cooling system is to|Underground temperatures being what they are, then, it’s the job of a geothermal heating and cooling system to transfer heat from the ground to your home or heat from your home to the ground, in keeping with the season. Either way, your home’s interior stays at the ideal temperature to keep you and your family happy month after month.

The device that handles the transfer is a geothermal heat pump. It continuously circulates water or some blend (predominantly antifreeze) between your home and loops of piping (predominantly fashioned of polyethylene, high-density polyethylene, PVC, or CPVC) installed in the ground. In Winter, the liquid is cold when it enters the ground. As it courses through the loops, it takes in heat from the earth and is returned to your home warm. In Summer, the process is reversed: warm liquid enters the loops, where it’s cooled by the cooler ground temperatures before it’s returned to your home. Want details? You’ll find more specific information on ground loops here.

The central point is that geothermal heating and cooling systems don’t produce energy. They’re not like central heating systems, which generate heat themselves. Instead, geothermal systems heat and cool your home by putting to use the energy already amply available beneath the earth’s surface. That’s why geothermal systems don’t only run quieter but also prove a lot more dependable, need less maintenance, have far longer lifespans, and are more environmentally friendly than conventional HVACs. That’s also why, ultimately, you’ll save considerably more more money by going geothermal.